If you JUST updated it, have Claude re-read it, this was the biggest thing for me. If you just created it, same thing. Even though Claude created the file, it has not read it in whatever special way Claude will read that file, which is silly, but once you realize this, and have Claude read it, it makes a difference. It will always load it from a new session, but if it changes or doesn't exist when you start a session it will be stale or empty.